Índice

It is not okay to call something a miracle without even trying to understand it. This is human developmental biology (human embryology, in terms of cells and molecules) for everyone curious enough to see it through, from the perspective of the business of becoming human as individuals and as species; making new humans; how it happens (cells do it, ALL of it); and common variations of the process. It cannot be made quite simple and be kept quite true, but we will move as far toward simple as we can without losing touch with sound evidence. Variations from the normal version of the process, particularly malformations and twinning and chimerism, figure prominently in the story because there is no better way to learn about the usual than to study the unusual and see what differences in the endings these observable differences at the beginnings can make. In this book, when technical terminology is the only way, or the best way, to say what needs to be said, it is defined and explained making the wo rds a worthwhile part of what is here to be learned. This book defines its own new field. We cannot claim to understand how anything [human] works [as human], with no effort at understanding the emergence of its form and functions. Old and new unanswered questions are waiting to be dug out from under old unquestioned answers about how becoming human unfolds. We will also address some popular and weighty, but deeply empty assertions about the circumstances and mechanisms of our beginnings and our ceaseless becoming. We will find fundamental questions from the humanitmes numanswerable except from biology. Human developmental biology is a foundational discipline within the humanities.

Índice: A Place to Start; Framing the Perspective; Schizophrenia, Brain Asymmetry, and Genetic Twin Studies of Multifactorial Inheritance; What It Means to be Human Has a Lot tr Do with Why ""Means"" Mean, Whrt It Means, if Anything; The Road through Syngamy and on through Embryogenesis; The Beginnings of Human Lives; Reviewing the Orthodoxy; Chorion, Amnion and the Vertebrate Body Plan; On the Zygosity of Twins; Most Twins Are Not Twins; Twins and Twinning in Perspective; Timing is Everything. Ocyte Maturation, Fertilization and Seasonal Rhythms; Twins and Handedness and Mirror-Imaging; Twins and Malformations; T... Etc.